US8114138B2

Movatterモバイル変換

Info

Publication number: US8114138B2
Application number: US12/333,260
Authority: US
Inventors: Daniel Nehls
Original assignee: Individual
Current assignee: Individual
Priority date: 2008-12-11
Filing date: 2008-12-11
Publication date: 2012-02-14
Also published as: US20100152781A1

Abstract

Template systems and methods of use are disclosed herein for use in conjunction with corresponding spinal fusion plates. Preferred templates are slotted to allow for use with distractor pins and a distractor. Additionally preferred templates include windows to allow the operating surgeon to have more visibility of the intervertebral area, including the graft. After the appropriate sized template has been placed against the targeted vertebrae, holding pins can be placed into the vertebral bodies to help guide the fusion plate and to compress the intervertebral space.

Description

FIELD OF THE INVENTION

The embodiments herein relate to template systems and methods useful in bone fixation procedures. More particularly, the teaching herein relate to improving current methods and systems directed to fusing one or more adjacent vertebrae.

BACKGROUND

The spine consists of a series of bone structures termed “vertebrae.” Between each vertebra is a flexible, connective tissue termed an “intervertebral disc” which secures one vertebra to another and functions as a shock absorber. Spinal fixation is a surgical technique in which one or more of the vertebrae of the spine are joined by an implant (e.g., a plate or rods.) to prevent relative movement of the spine, with the goal of live bone eventually fusing the adjacent vertebrae together.

Patients requiring spinal fusion typically suffer from either neurological deficits or severe pain which has not responded to conservative treatment. Typical conditions that are treated by spinal fusion procedure non-exclusively include: degenerative spinal conditions, discogenic pain, spinal tumor, vertebral fracture, scoliosis, kyphosis, spondylolisthesis, spondylosis, and other conditions that causes instability or pain in the spine.

Typically a spinal fixation procedure does not connect the patient's original vertebrae directly together; rather the intervertebral disc is usually completely or partially removed (disectomy) and/or one or more entire vertebral bodies are removed (corpectomy). The space remaining from the removed discs and vertebral bodies after a disectomy or corpectomy is typically replaced by a graft positioned between adjacent vertebrae to maintain proper length in the spinal column. After the surgery, it is desired that living bone from the vertebrae spans the inter-body graft thereby fusing the adjacent vertebrae together.

Traditionally, interbody grafts are fashioned from bone taken from a patient's skeleton, and are also referred to as “autografts.” As the harvesting of an autograft is painful for the patient, many surgeons now prefer the use of “allografts” which are harvested from a body other than the patient's. Interbody grafts may also be formed from synthetic materials such as titanium, carbon fiber and plastics. Unfortunately, grafts are associated with a relatively high rate of dislodgement due to the patient's neck movement during the healing process. To minimize the risk of dislodgement of the interbody graft posteriorly, toward the spinal cord, surgeons routinely mortise the graft by drilling a shelf into the vertebrae. To minimize the risk of dislodgement of the interbody graft anteriorly, surgeons routinely place a fusion plate across the inner space and secure it with screws extending into the vertebrae.

Placement of an anterior cervical plate with a screw fixation is effective in preventing interbody graft dislodgement toward the esophagus and also enhances fusion by providing rigid fixation between the vertebrae.

Presently, in performing a disectomy or corpectomy, a distractor is used to spread the adjacent vertebrae so that the disc or vertebral body of interest can be removed. In use, a pair of distractor pins having heads for engaging with a distractor are screwed into the vertebrae adjacent to the disectomy or corpectomy site. One pin is placed in the superior vertebra, and a second pin is placed in the inferior vertebra. The distractor is then coupled to the heads of pins on the upper and lower vertebrae, above and below the site, and the vertebrae are then mechanically spread apart, for aiding in the removal of any remaining portion of the deteriorated disc or vertebral body, and also for creating a gap for placing the graft. According to most traditional methods, the distractor and distractor pins are removed after the bone graft is positioned, and before a fusion plate is fixed onto the lower and upper vertebrae.

The above-described method has many disadvantages, one being that it relies on the natural weight of the spine to compress the intervertebral graft between the upper and lower vertebral bodies. Natural compression alone is often insufficient as it can create undesirable space between the vertebral members and thus reduces the likelihood that fusion will occur. U.S. Pat. No. 6,648,891, to Kim (which is hereby expressly incorporated by reference herein in its entirety) attempted to address this issue by describing a system that allows a slotted fusion plate to be screwed into the desired vertebral bodies while the distractor and the distractor pins remain in the vertebrae (See Kim, cols. 2-3). More specifically, these plates include the upper and lower slots configured to be used with distractor pins, and therefore allow a surgeon to utilize a distractor to apply “mechanical compression” on the intervertebral graft as the final fusion plate is secured.

Unfortunately, the fusion plates provided by Kim are not a complete solution. Even though the slotted plates are configured to be used while the distractor pins are still attached to the vertebral bodies, they do not allow for an unobstructed view of the spine, including the intervertebral space where the graft is positioned during the operation. Without an unobstructed view, surgeons are more likely to accidentally position the screw into the graft, which could push it into the patient's spinal cord. It is important to note that adding a central window to the Kim plates would not be an obvious modification. To explain, it is first noted that the screw holes on the plate need to be of a considerable size to accommodate the final screws. This is important because the width of the plate is limited by the width of the vertebral bodies, and thus there is a limited amount of space on the plate for both upper and lower slots and the screw holes. Due to this constraint, the bigger the screw holes are on the plate, the less available space there will be for the slots, and vice versa. This sizing and positioning problem is compounded if the final plate also includes a central window for viewing the graft. Having a large viewing window, screw holes, and distractor pin slots on the final plate can also compromise the strength of the final plate, especially if it is a smaller sized plate.

Thus, there is a need in the art for improved procedures and systems for applying a fusion plate to a patient's spine, following a corpectomy or disectomy, that provide sufficient pressure to the spine and an optimum viewing area for the surgeon to work, without utilizing potentially weakened, or poorly configured plates.

SUMMARY OF THE INVENTION

Preferred embodiments are directed to templates adapted to be removably positioned over superior and inferior vertebral bodies and a first intervertebral space, and having a top section configured to be positioned on the superior vertebral body and comprising a first vertical slot adapted to receive a first distractor pin and that divides the top section into first and second upper corner areas, wherein at least one of the upper corner areas comprise a first holding pin aperture; a bottom section configured to be positioned on the inferior vertebral body and comprising a second vertical slot adapted to receive a second distractor pin and that divides the bottom section into first and second lower corner areas, wherein at least one of the lower corner areas comprises a second holding pin aperture; and a first window positioned between the top and bottom sections and configured to be positioned over the first intervertebral space.

Preferably, the first and second holding pin apertures are vertically aligned with another and the four corner areas each include a holding pin aperture.

According to specific embodiments, the first and second holding pin apertures are variable-size apertures that individually include multiple positions for a holding pin to be placed.

Preferably, the first vertical slot partially bifurcates the top section down the middle of the template and the second vertical slot partially bifurcates the bottom section up the middle of the template.

Alternatively, the templates herein can further include a middle section configured to be positioned against a middle vertebral body in between the superior and inferior vertebral bodies. More specifically, the first window can be positioned between the top and middle sections of the template and can be configured to be positioned over the first intervertebral space between the superior and middle vertebral bodies. The template can further comprise a second window positioned between the bottom and middle sections of the template and can be configured to be positioned over a second intervertebral space between the inferior and middle vertebral bodies.

Further embodiments are directed to methods of using the templates herein to select a fusion plate for implanting onto a superior and inferior vertebral body having a graft implanted between a first intervertebral space comprising: (a) inserting a first distractor pin into the superior vertebral body and a second distractor pin into the inferior vertebrae; (b) engaging said distractor pins with a distractor; (c) compressing the intervertebral space and graft with the distractor; (d) providing a template, (e) placing the template on the compressed superior and inferior vertebrae such that the first vertical slot receives the first distractor pin, the second vertical slot receives the second distractor pin, and the first window is positioned over the first intervertebral space; and (f) selecting a final fusion plate for implantation onto the superior and inferior vertebral bodies that comprises first and second screw holes aligned with the first and second holding pin apertures on the template.

Further methods are directed to using the templates herein for implanting a fusion plate onto a superior and inferior vertebral body having a graft implanted between a first intervertebral space comprising: (a) inserting a first distractor pin into the superior vertebral body and a second distractor pin into the inferior vertebrae; (b) engaging said distractor pins with a distractor; (c) compressing the intervertebral space and graft with the distractor; (d) providing a template, (e) placing the template on the compressed superior and inferior vertebrae such that the first vertical slot receives the first distractor pin, the second vertical slot receives the second distractor pin, and the first window is positioned over the first intervertebral space; (f) selecting a final fusion plate for implantation onto the superior and inferior vertebral bodies that comprises first and second screw holes aligned with the first and second holding pin apertures on the template; (g) placing a first holding pin into the superior vertebral body through the first holding pin aperture; (h) placing a second holding pin into the inferior vertebral body through the second holding pin aperture; (i) removing the template from the superior and inferior vertebral bodies; (j) removing distractor pins from the superior and inferior vertebral bodies; (k) placing the fusion plate onto the superior and inferior vertebral bodies such that the first and second holding pins pass through the first and second aligned screw holes on the fusion plate and compress the first intervertebral space; and (l) securing said fusion plate to the superior and inferior vertebral bodies.

BRIEF DESCRIPTION OF THE DRAWINGS

It will be appreciated that the drawings are not necessarily to scale, with emphasis instead being placed on illustrating the various aspects and features of embodiments of the invention, in which:

FIG. 1 is a perspective view of a preferred template being positioned on adjacent vertebral bodies.

FIG. 2 is a perspective view of holding pins being inserted though a preferred template positioned on adjacent vertebral bodies.

FIG. 3 is an exploded view of a preferred final plate being aligned to adjacent vertebral bodies through the use of holding pins.

FIG. 4 is a perspective view of a preferred final plate in the process of being secured to adjacent vertebral bodies.

FIG. 5 is a side view ofFIG. 4, showing a preferred final plate in the process of being secured to adjacent vertebral bodies

FIG. 6 is a perspective view showing a preferred final plate secured to adjacent vertebral bodies.

FIG. 7 is a planar view of an alternative template.

FIG. 8 is a planar view of a narrow alternative template

FIG. 9 is a planar view of a multi-size template.

FIG. 10A is a view of a multi-level final plate secured to three vertebrae.

FIG. 10B is a view of a multi-level final plate.

FIG. 10C is a view of a multi-level template.

DETAILED DESCRIPTION OF THE ILLUSTRATED EMBODIMENTS

Embodiments of the present invention are described below with reference to the above described Figures. It is, however, expressly noted that the present invention is not limited to the embodiments depicted in the Figures, but rather the intention is that modifications that are apparent to the person skilled in the art and equivalents thereof are also included.

According to preferred systems and methods, a surgeon first removes the intervertebral disc (disectomy) and/or one or more vertebral bodies (corpectomy), or portions thereof, by using a distractor. In general, distractor pins14aand14bare individually fixed to

vertebral bodies

24aand24brespectively, which are positioned superior and inferior to the designated disc or section being removed. Typically, the distractor pins14aand14bare screwed into the

vertebral bodies

24aand24b. A distractor tool engages the exposed heads of the pins (14aand14b) and expands to mechanically separate the

vertebral bodies

24aand24bto allow the surgeon better access to the designated disc or section to be removed.

Distractors and methods of distracting are known in the art and any suitable one can be used with the teachings herein. One non-exclusive example of a distractor/retractor that can be used for separating vertebral bodies is disclosed in U.S. Patent Application No. 2006/0084844, published Apr. 20, 2006 to Daniel G. Nehls, which is hereby expressly incorporated by reference herein in its entirety. After the designated disc material and/or vertebral body is removed, agraft22 can be inserted into the resulting space, using techniques and materials that are well known in the art. The surgeon then preferably uses the distractor tool which is engaged with the distractor pins14aand14bto compress theintervertebral space18 and more preferably thegraft22. This compression can allow thegraft22 to have better contact with the vertebral endplates, and thus increase the chances of incorporation.

Preferred methods and systems provided herein, are directed to using atemplate2 after thegraft22 has been positioned in theintervertebral space18 and before the implantation of thefinal plate26.

Template

FIG. 1 depicts a perspective view of apreferred template2 being aligned over a superiorvertebral body24aand inferiorvertebral body24b. The term “template” as used herein generally relates to devices that are not permanent implants and have one or more windows configured to allow a surgeon to view an intervertebral space. Preferably templates include two or more apertures to allow holding pins or other markers to be placed into the surrounding vertebrae that guide or mark where the final plate will be positioned. While thetemplate2 depicted inFIGS. 1 and 2 is a preferred model and is predominately described herein, the described features and methods of thistemplate2 can expressly be used on other template configurations described herein, such as2a,2b,2c,2d.

FIGS. 1,2,7-9, depict

templates

2,2a,2b, and2cthat are designed to be positioned on two vertebral bodies and are useful for corpectomies and single-level disectomies. Alternatively, and as shown inFIG. 10c,longer templates2dhaving three or more sections individually configured to be placed on three or more

different vertebrae

24a,24band24ccan be used for multi-level disectomies, for example

According to preferred embodiments, atemplate2 can include anupper section10 configured to be positioned on the superiorvertebral body24aand alower section12 configured to be positioned on the inferiorvertebral body24b. According to advantageous embodiments, the template includes awindow16 configured to provide the surgeon with a view of theintervertebral area18, and/or theinterbody implant22. Preferably thewindow16 is located in the center of thetemplate2, or substantially so, or at other locations that allow the surgeon to view theintervertebral area18, and/or theinterbody implant22.

Amulti-level template2dcan include two or more windows, such as anupper window16aand alower window16b, to view the two or more intervertebral spaces it covers when positioned on three or more

vertebral bodies

24a,24b, and24c. More particularly the multiple windows can be separated by one ormore template sections44 configured to be positioned on a middle vertebral body24c. Alternatively, a multilevel template can include one large window configured to view both intervertebral spaces, and lack the separating section.

Templates having awindow16 configured to view theinterbody18 and/orgraft22 is highly advantageous as it allows the surgeon to better ascertain the position of thefinal plate26. Additionally, thewindow16 lessens the chances of the surgeon accidentally placing a holdingpin20band20c, or final screw28a-d, into thebone graft22 which could dislodge it and push it into the spinal cord. According to preferred embodiments, thewindow16 can be an open hole or a hole covered by a transparent material such as clear plastic or glass, for example.

According to more specific embodiments, theupper section10 of thetemplate2 can be partially bisected by avertical slot6aconfigured to receive afirst distractor pin14aand that effectively divides theupper section10 of thetemplate2 into aright corner area7aand leftcorner area7b. According to more specific embodiments, thevertical slot6abegins in the middle of the upper perimeter of thetemplate2, or substantially so, and bisects downward towards the upper border of thetemplate window16 to anend point36. Likewise, it is preferred that thelower section12 of thetemplate2 is partially bisected by a secondvertical slot6b, configured to receive asecond distractor pin14b, and that effectively divides thelower section12 of thetemplate2 into aright corner area7dand a left corner area7c. According to more specific embodiments, thevertical slot6bbegins in the middle of the lower perimeter of thetemplate2, or substantially so, and bisects upwards towards the lower border of thetemplate window16 to anend point38.

According to advantageous embodiments where the

slots

6aand6bare located in the middle of thetemplate2, or substantially so, they are useful for centering thetemplate2 and the correspondingfinal plate26 along the vertebral mid-line. The end points36 and38 of the

slots

6aand6bare useful in aligning thetemplate2 against the distractor pins14aand14b. Additionally, the end points36 and38 are helpful in preventing over-compression by the distractor pins which can damage thegraft22.

For amulti-level template2dtheupper slot6acan bisect the top portion of the template into left and

right corner areas

7band7aas it traverses downward towards the upper border of theupper window16a. Likewise thelower slot6bcan bisect the lower portion of the template into left andright corner areas7cand7das it traverses upwards towards the lower border of thelower window16b. Alternatively the upper and lower slots can bisect towards a single large window that allows viewing of two or more intervertebral spaces.

Preferred templates described herein can be made of any suitable material including titanium, surgical steel, aluminum, or other metal, or hard plastic, for example.

It is preferred that the size and shape of each differentlysized template2 corresponds to a certain size and shape offinal plate26. Examples of current fusion plates used in the art, are those produced by EBI Biomet, Inc., Dupuy AcroMed, Inc., and Spinal Concepts, Inc, to name a few. Accordingly, it is preferred to providetemplates2 that align with different sizes and designs of these and other available plates.

It is highly preferable that the screw holes30a-dof thefinal plate26 align with the pin apertures4a-don thetemplate2 if theplate26 were to be overlaid on top of thetemplate2. The alignment of thetemplate2 with thefinal plate26 ensures that the holding pins20band20care correctly positioned into the

vertebral bodies

24aand24band that they effectively guide the final plate's screw apertures30a-dto their appropriate positions on the

vertebral bodies

24aand24bto receive the final screws28a-d.

More specifically, thetemplate2 can include 1, 2, 3, 4, 5, 6 or more holding pin apertures that align with one or more, or all, screw apertures located on thefinal plate26. Further embodiments can utilize 2, 3, 4, 5, 6, or more holding pins depending on the preference of the surgeon, the number of apertures on the template, and the configuration of the template. It is preferred that the templates provided herein include four apertures as most fusion plates have four apertures, and this allows the surgeon to determine where all of the final screws28a-dwill be secured into the

patients vertebrae

24aand24b. In more preferred embodiments, it is advantageous that thetemplates2 provided herein include the same number of holding pin apertures as there are screw holes on thefinal plate26.

The holding pin apertures4a-d, are preferably located in the corner areas7a-dor around the sides of thetemplates2. Likewise, the screw holes30a-dare also preferably positioned in the corner areas or around the sides of thefinal plate26.

As preferred embodiments only utilize two holding pins, it is also readily contemplated herein to utilize templates that have the same number of holding pins apertures as holding pins used. This number could be two, three, four, or more for example. For embodiments directed to templates having a number of holding pin apertures that is smaller than the number of screw apertures on the corresponding final plate, it is preferred that the screw apertures that do not correspond to a holding pin aperture are positioned correctly against the

vertebrae

24aand24bwhen the targeted screw holes are placed over the holding pins. For example, if a template only had two holdingpin apertures4band4c(4aand4dare not present), it is preferred that when the aligned screw holes30band30cof thefinal plate26 are placed over the holdingpins4band4c, the remaining screw holes30aand30dare positioned in their proper place along the superior and inferior

vertebral bodies

24aand24bfor the

final screws

28aand28dto properly secure theplate26. For embodiments where only two holding pin apertures are used, it is preferred that they are positioned in vertically aligned corners or alternatively in horizontally or diagonally aligned positions.

According to alternative embodiments, themulti-level template2dcan include six or more holding pin apertures4a-fthat align with the six screw holes30a-fon themulti-level plate26a. Preferably, the separatingsection44, can includepin holes4fand4econfigured to receive their own holding pins. Further embodiments entail only 1 row of vertically aligned holding pin apertures, such as only4b,4f,4cor4a,4e, and4d. Alternatively, the multi-level template could have only two holding pin apertures that are vertically aligned, such as4band4cor4aand4d.

The corner areas of thetemplate2 and/or thefinal plate26 can be any suitable geometrical shape, including right angles, circular, semi-circular, chamfered, filleted, or bull-nosed, or substantially so, for example.FIG. 7 depicts a template2ahaving substantially circular corner areas,FIG. 8 depicts atemplate2bhaving substantially semi-circular corner areas. Both of thesetemplates2aand2binclude one ormore openings40 surrounding the pin holesapertures4a, b, c, anddto allow better viewing of the vertebrae area such as to improve proper placement of the holdingpin20band20c.

After the appropriatesized template2 is determined, the surgeon can then select a correspondingfinal plate26. If the surgeon already knows the size and shape of thefinal plate26, it may be possible to utilize asingle template2 to determine the proper position of thefinal plate26 on the targeted

vertebrae

24aand24b. However, as most surgeons will not immediately know the size of thefinal plate26, he can individually test multiple sizes and/or shapes oftemplates2 against the

vertebrae

24aand24bwhile the distractor is compressing the distractor pins14aand14buntil the appropriate size and shape of thefinal plate26 can be determined.

According to alternative embodiments, instead of utilizing multiple different templates to ascertain the correct size of final plate, a surgeon could use asingle multi-size template2csuch as provided inFIG. 9, for example.Multi-size templates2cpreferably include variable-size holding pin apertures42a-dthat individually include multiple positions for a holding pin to be placed. More specifically, the multiple positions within the variable-size holding pin apertures42a-dcorrespond to different sizes of final plates and are preferably incrementally separated. More specifically, the variable-size holding pin apertures42a-dcan include two, three, four, five, or more positions to hold a holding pin.FIG. 9, as an example, depicts variable-size holding pin apertures42a-dhaving three positions that corresponds with various sizes of final plates: 14, 16, 18 mm. After placing themulti-size template2cagainst the

vertebrae

24aand24band theintervertebral space18, the surgeon could look at the position of variable-size apertures42a-dand ascertain the proper size of thefinal plate26 and place two or more holding pins into the corresponding position within two or more variable-size holding pin apertures42a-d. A final plate having screw holes with variable-size positions is also readily contemplated to be used with the teachings herein.

Methods of Use

In preferred methods, after placing thegraft22 into theinterbody space18 the surgeon aligns the upper and

lower slots

6aand6bof the template onto the upper and lower distractor pins14aand14brespectively and positions thetemplate2 towards the superior and inferior

vertebral bodies

24aand24b. In highly advantageous embodiments, it is preferred that the surgeon uses a distractor and/or retractor engaged with the distractor pins14aand14bto mechanically compress the superior and inferior

vertebral bodies

24aand24bas thetemplate2 is positioned downward toward them. This mechanical compression is advantageous as it can apply greater pressure to thegraft22 than the natural compression of the

vertebral bodies

24aand24bby themselves. By increasing the pressure, the surgeon significantly increases the chances of a successful fusion.

Preferably while thetemplate2 is positioned against the compressed

vertebral bodies

24aand24b, the surgeon can place holdingpins20band20cin theapertures4band4c. Preferably, the holding pins20band20care made of metal, such as titanium or stainless steel, and are screwed into the vertebrae, although other suitable methods can be used. More specifically, it is preferred that the holding pins20band20cinclude a threaded portion configured to be secured within the vertebra and an exposed portion configured to pass through its designatedaperture4band4c. While different numbers of apertures and holding pins can be used with the systems and methods provided herein, it is preferred that only two holding pins are utilized. More specifically it is preferred that the two holding pins are positioned on the same side of each other, individually in apertures that are vertically aligned from one another. For example, as depicted inFIG. 2, holdingpins20band20care respectively placed in theaperture4blocated in the upperleft corner7band the aperture4clocated in the lower left corner area7c. In alternative preferred embodiments, holding pins can individually be place in the upperright aperture4aand the bottomright aperture4d(not shown).

In further non-preferred embodiments, the two holding pins can be placed in apertures that are positioned diagonally from one another. For example, holding pins can individually be placed in the upperleft corner7band the lowerright corner7dof the template, or alternatively in the upperright corner7aand the lower left corner7cof thetemplate2. In still further non-preferred embodiments, the 2 holding pins can be placed in apertures that are positioned horizontally from one another, for example the upper left and right7b7aor lower left and right corner areas7c7d. As will be explained below, this is especially not advantageous because the horizontally positioned holding pins will not allow for any vertical compression of theinterbody graft22 when thefinal plate26 is implanted.

According to preferred embodiments, the holding pins20band20care not designed to permanently secure thetemplate2 to the

vertebral bodies

24aand24b, but rather serve as guides for thefinal plate26 and to allow for vertical compression of theintervertebral space18. According to preferred embodiments, the apertures of thetemplate4band4cand the holding pins20band20care configured such that the surgeon can readily remove thetemplate2 from the

vertebral bodies

24aand24bwithout having to remove the holding pins20band20c. More specifically, theapertures4band4cadvantageously, can have a larger diameter than the holding pins20band20c. In more specific embodiments, it is preferred that the holding pins20band20care positioned in the middle of theapertures4band4con the template, or substantially so. Additionally, it is preferred that thetemplate2 can be removed while the distractor pins14aand14bare still inserted into their

respective vertebrae

24aand24b, regardless of whether they are engaged or unengaged with a distractor.

While preferred embodiments provided herein are directed to systems and methods using holding pins20band20c, it is further contemplated to use other non-preferred means for marking the position of thefinal plate26. Any suitable visual markers can be utilized with thetemplates2 provided herein to guide the position of the final plate, including but not limited to etchings, dyes, pen or pencil markings, or ink, for example. The above markers can be made in one or more holding pin apertures in the template or can be made to indicate the perimeter of the final plate, for example. Non-pin embodiments are not preferred as they do not allow for vertical compression of theintervertebral space18.

After the holding pins20band20care placed into the vertebrae, thetemplate2 and distractor pins14aand14bcan be removed. After the distractor tool is disengaged from the distractor pins14aand14band/or the distractor pins14aand14bare removed from the

vertebral bodies

24aand24b, the intervertebral space will return to its natural uncompressed state. Alternatively distractor pins can be left in for enhanced compression and the final plate can be placed according to the methods of U.S. Pat. No. 6,648,891. Preferably, the holding pins20band20care left in the

vertebral bodies

24aand24bas guides for thefinal plate26 and to allow for compression of theintervertebral space18 as thefinal plate26 is secured. More specifically, it is preferred thatapertures30band30cof thefinal plate26 are configured such that when they slide down the holding pins20band20ctowards the

vertebral bodies

24aand24b, pressure will force the exposed (top) portion of the holding pins20band20cto converge towards each other (FIGS. 4 and 5), and the bottom portion of the holding pins20band20cembedded in the

vertebral bodies

24aand24bto diverge from each other (FIG. 5). This manipulation of the holding pins20band20ccauses vertical compression on theintervertebral space18 and preferably theinterbody graft22. Advantageously, this vertical compression is equal to, or similar to the original compression of the

vertebral bodies

24aand24bgenerated by the distractor and the distractor pins14aand14b. Alternatively it is lesser compression than obtained by the distractor.

Once theplate26 is pressed against the

vertebral bodies

24aand24band theintervertebral space18 is compressed by the holding pins20band20c, the

final screws

28aand28dcan be secured through the

open holes

30aand30das shown inFIG. 4. After the

screws

28aand28dare secured to the

vertebral bodies

24aand24bthe compression of theintervertebral space18 is maintained and the holding pins20band20ccan be removed without allowing expansion of theintervertebral space18. Final screws can then replace the holding pins20band20cthrough theholes30band30cto permanently affix thefinal plate26 to the

vertebral bodies

24aand24b.

The invention may be embodied in other specific forms besides and beyond those described herein. The foregoing embodiments are therefore to be considered in all respects illustrative rather than limiting, and the scope of the invention is defined and limited only by the appended claims and their equivalents, rather than by the foregoing description.

Claims

What is claimed is:

1. A method of using a template to select a fusion plate for implanting onto a superior and inferior vertebral body having a graft implanted between a first intervertebral space comprising:

(a) inserting a first distractor pin into the superior vertebral body and a second distractor pin into the inferior vertebrae;

(b) engaging said distractor pins with a distractor;

(c) compressing the intervertebral space and graft with the distractor;

(d) providing a template comprising

(i) a top section configured to be positioned on the superior vertebral body and comprising a first vertical slot adapted to receive the first distractor pin and that divides the top section into first and second upper corner areas, wherein at least one of the upper corner areas comprise a first holding pin aperture;

(ii) a bottom section configured to be positioned on the inferior vertebral body and comprising a second vertical slot adapted to receive the second distractor pin and that divides the bottom section into first and second lower corner areas, wherein at least one of the lower corner areas comprises a second holding pin aperture; and

(iii) a first window positioned between the top and bottom sections and adapted to be positioned over the first intervertebral space;

(e) placing the template on the compressed superior and inferior vertebrae such that the first vertical slot receives the first distractor pin, the second vertical slot receives the second distractor pin, and the first window is positioned over the first intervertebral space; and

(f) selecting a final fusion plate for implantation onto the superior and inferior vertebral bodies that comprises first and second screw holes aligned with the first and second holding pin apertures on the template.

2. The method ofclaim 1, wherein the first and second holding pin apertures on the template are vertically aligned with another.

3. The method ofclaim 1, wherein the four corner areas of the template each include a holding pin aperture.

4. The method ofclaim 1, wherein the first and second holding pin apertures are variable-size apertures that individually include multiple positions for a holding pin to be placed.

5. The method ofclaim 1, further comprising a middle section configured to be positioned against a middle vertebral body in between the superior and inferior vertebral bodies.

6. The method ofclaim 5, wherein the first window is positioned between the top and middle sections of the template and is configured to be positioned over the first intervertebral space between the superior and middle vertebral bodies and wherein the template further comprises a second window positioned between the bottom and middle sections of the template and is configured to be positioned over a second intervertebral space between the inferior and middle vertebral bodies.

7. A method of using a template for implanting a fusion plate onto a superior and inferior vertebral body having a graft implanted between a first intervertebral space comprising:

(b) engaging said distractor pins with a distractor;

(c) compressing the intervertebral space and graft with the distractor;

(d) providing a template comprising

(e) placing the template on the compressed superior and inferior vertebrae such that the first vertical slot receives the first distractor pin, the second vertical slot receives the second distractor pin, and the first window is positioned over the first intervertebral space;

(f) selecting a final fusion plate for implantation onto the superior and inferior vertebral bodies that comprises first and second screw holes aligned with the first and second holding pin apertures on the template;

(g) placing a first holding pin into the superior vertebral body through the first holding pin aperture;

(h) placing a second holding pin into the inferior vertebral body through the second holding pin aperture;

(i) removing the template from the superior and inferior vertebral bodies;

(j) removing distractor pins from the superior and inferior vertebral bodies;

(k) placing the fusion plate onto the superior and inferior vertebral bodies such that the first and second holding pins pass through the first and second aligned screw holes on the fusion plate and compress the first intervertebral space; and

(l) securing said fusion plate to the superior and inferior vertebral bodies.

8. The method ofclaim 7, wherein the first and second holding pin apertures on the template are vertically aligned with another.

9. The method ofclaim 7, wherein the first and second holding pin apertures are variable-size apertures that individually include multiple positions for a holding pin to be placed.

10. The method ofclaim 7, further comprising a middle section configured to be positioned against a middle vertebral body in between the superior and inferior vertebral bodies.

11. The method ofclaim 10, wherein the first window is positioned between the top and middle sections of the template and is configured to be positioned over the first intervertebral space between the superior and middle vertebral bodies and wherein the template further comprises a second window positioned between the bottom and middle sections of the template and is configured to be positioned over a second intervertebral space between the inferior and middle vertebral bodies.